Multi-gallon capacity plastic containers having removable plastic lids or covers are widely used for the storage and transportation of liquid and solid materials, e.g., materials in granular or powder form. For some applications, the lids may be single use, i.e. they may be thrown away after the container has been opened, typically because all of the contents of the container are dispensed after the lid is removed. For other applications a reusable lid must be provided, for example, when it is desired to use only a portion of the contents of the container and to then store the partially filled container for future use. In many cases the reusable lid may have to make a secure fit, so as to prevent leaking of the contents of the container after the lid has been reapplied. Having a secure fit is of particular concern if the container is filled with material that is toxic or irritating to the skin and is used in or around a residence where small children are present, since their curiosity may cause them to remove the lid to view the contents of the container. Safety concerns demand that reusable lids not only make a substantially leak-proof fit with the container but also be difficult for children to remove, either accidentally or purposefully. However, as practical matter, commercial production of containers and lids that satisfy existing safety concerns necessarily requires control of manufacturing costs.